Date of Award


Degree Type


Degree Name

Bachelor of Nursing Honours


School of Nursing


Faculty of Health and Human Sciences

First Advisor

Dr Sue Nikoletti


Fibreoptic endoscopy is a common and relatively safe diagnostic and therapeutic procedure used to examine the gastrointestinal tract. Previous research has established that oxygen desaturation is common among patients undergoing endoscopy and is one of the few complications which may arise during, and after the procedure. Oxygen saturation (Sa02) is a measurement of the percentage of oxygen carried by the haemoglobin and can be measured noninvasively and accurately using a pulse oximeter. Oxygen desaturation is generally described as Sa02 levels at or below 90%. Currently there are no clear guidelines for the duration of Sa02 monitoring following endoscopy. It is also unclear whether all patients, or some groups of patients, would benefit most from such monitoring. The purpose of this study was twofold. Firstly, the study sought to describe the oxygen saturation levels in patients prior to, during, and after endoscopy using pulse oximetry. Secondly it sought to identify patient characteristics (variables) which may help to predict which patients are most vulnerable to desaturation. The study was conducted within the Gastroenterological Department of a major teaching hospital in Perth, Western Australia, using a convenience sample of 218 patients. The results have clearly shown there to be a decrease in the mean Sa02 relative to baseline after endoscopy, and that there is an increase in the range and variance of Sa02 measurements after endoscopy. There was no statistically significant difference between the mean SaO2 measurement for patients undergoing gastroscopy and colonoscopy. There was a greater incidence of desaturation after endoscopy compared with during endoscopy. The majority of desaturation events occurred both within the first five minutes of the procedure, and within the first five minutes of the recovery phase. From the literature, baseline oxygen saturation levels, age, smoking history, sedation, and cardiac and respiratory problems were identified as possible predictors of oxygen desaturation. Following hierarchical multiple regression analysis, baseline Sa02 level and age made a statistically significant contribution to the prediction of desaturation among patients undergoing endoscopy. The addition of the variables smoking history, level of sedation, cardiac condition, and respiratory condition to the regression analysis did not significantly improve the prediction of desaturation. Age and a low baseline SaO2 were identified in this study as being the variables which may help to predict which patients will be at a greater risk of desaturation. This study has indicated that the identification of those variables that contribute to an increased risk of desaturation, and further monitoring of high risk patients using pulse oximetry, allows for nursing interventions to be implemented before the potentially serious consequences of desaturation occur. The recommendations of this study are to continue pulse oximetry monitoring and to administer supplemental oxygen for high risk patients into the recovery period.